Disc tumbler cylinder and key for a lock

ABSTRACT

The lock plug has several slots, each holding three disc tumblers spring biased into locking positions, two of which tumblers are moved up and the remaining one down by the key and its camming shoulders to release the rotatable plug.

United States Patent [72] Inventor Ernst Keller 6, Querslrasse, 8805 Richterswil, Switzerland [21 Appl. No. 797,733

22 Filed Feb. 10, 1969 [45] Patented May 11, I971 [32] Priority Feb. 9, 1969 [33] Switzerland [54] DISK TUMBLER CYLINDER AND KEY FOR A LOCK 7 Claims, 9 Drawing Figs.

[52] US. Cl 64, 70/377, 70/406, 70/419 [51] Int. Cl E05h 15/14, E05b 29/12 [50] Field of Search 70/ 364, 358, 375, 376, 406, 407, 419-421 References Cited UNITED STATES PATENTS Shinn Molinare Jacobi Olson Gray..... Olson Shinn FOREIGN PATENTS Germany Primary Examiner-Marvin A. Champion Assistant Examiner-Robert L. Wolfe Art0meyWaters, Roditi, Schwartz & Nissen 70/377X 70/377X 70/377X 70/364 70/364 70/406 70/364X ABSTRACT: The lock plug has several slots, each holding three disc tumblers spring biased into locking positions, two of which tumblers are moved up and the remaining one down by the key and its camming shoulders to release the rotatable plug.

DISK TUMIILER CYLINDER AND KEY FOR A LOCK BACKGROUND OF THE INVENTION The invention relates to a lock and therefor the combination of a disc tumbler cylinder and a key. Conventional cylinders of this kind are not very secure against being unlocked by unauthorized persons who lack the right key. A sufficiently skillful person can contact the individual tumblers and, by revolving the plug through the lateral play of the tumblers move the tumblers one by one into their unlocking position, thereby releasing the plug, which is now free to turn.

The security of a cylinder lock of this kind increases in proportion to the number of disc tumblers it has. Since the length of the plug is limited, the possible number of tumblers is likewise limited. It has been suggested that each tumbler slot in the plug should hold two tumblers. However, since the operating surface of the key moves the tumblers in the same direction and through the same distance, the security afforded by the lock is not appreciably increased.

SUMMARY OFTHE INVENTION The purpose of the invention is to produce a disc tumbler cylinder of the kind described and which is virtually pickproof.

The invention fundamentally comprises in combination a disc tumbler cylinder and a key, and includes a revolving plug, a plurality of movable disc tumblers in the plug and moved by the key to release the plug, an outer cylinder cooperating with the tumblers in their locking positions, an opening in each tumbler to form a keyway, and a web incorporated by the key. The novelty of the invention relates to a plurality of slots in the plug, each slot holding a set of at least three tumblers free to slide therein between locked and unlocked positions for the plug, and camming means incorporated on at least one face of the key web for moving at least some of the tumblers to release the plug, and for moving at least one of these tumblers in a direction opposite to that in which the other tumblers of the same set move.

This construction of the cylinder makes it virtually impossible for an unauthorized person to manipulate the individual disc tumblers andto push them into their unlocking positions, since in each tumbler set at least one tumbler must be moved in the direction opposite to that in which the other tumblers must move.

The novel construction of the invention, as will be apparent from the following detailed description, has the further ad vantage that the more the first or last tumbler of a set is pushed towards its unlocking position, the more the adjacent tumbler of the neighboring set is pressed into its locking position by the resilient means common to these two tumblers.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described, with reference to the FIGS. of the drawings, wherein:

FIG. 1 is a longitudinal section of the cylinder of the invention, with the key inserted;

FIG. 2 is a longitudinal section corresponding to FIG. I, but with the key removed and the tumblers in their locking positions;

FIG. 3 is a side view of the plug without its tumblers;

FIG. 4 is a cross section taken along line IV-lV of FIG. 1;

FIG. 5 is a perspective view of some of the tumblers, in their locking positions;

FIG. 6 is a perspective view of some of the tumblers, in their unlocking position;

FIG. 7 is a side view of the web of the key; and

FIGS. 8 and 9 are sectional views respectively taken along lines VIII-VIII and IX-IX of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the FIGS. the disc tumbler cylinder, as illustrated in FIGS. 1, 2, and 4, comprises a cylinder 1 and a plug 2 mounted therein to freely rotate. The plug embodies a keyway 3 and a series of slots 4 that extend vertically to the keyway. Each slot holds a set of three disc tumblers 5, 6, and 7, which are free to move up and down in the slot. When the key is not inserted into the keyway, the tumblers, in their locking positions, project into lengthwise slots 9 and 10 in the cylinder 1 and thereby prevent the plug 2 from turning in the cylinder. Springs 11 and 12 press the tumblers 5, 6, and 7 into their locking positions. These springs are arranged in recesses 44 next to the slots 4 in the plug 2 and act on toes 5a, 6a, and that are incorporated in the sides, and project at right angles to the planes, of the tumblers. As shown in FIGS. 5 and 6, a respective spring 11 is compressed between a toe 5a of the last tumbler, 5, of one set and the toe 7a of the adjacent, first tumbler, 7, of the next set. The middle tumbler 6 of each set is pressed into its locking position by a separate spring 12, which is compressed between the toe 6a and the plug 2. Likewise, respective springs 12 act on the first tumbler, 7, of the first set and the last tumbler, 5, of the last set. When in their locking positions, the tumbler 5 of each set projects into the slot 9 and the tumblers 6 and 7 into the slot 10. To lock and unlock, some tumblers, therefore, are moved up while others are moved down.

The key 8, which is shown separately in FIGS. 7 to 9, has a web 13, each face of which incorporates a camming shoulder I4 or 15 having a shape that, with respect to the longitudinal center line of the web 13, is the opposite of the shape of the other shoulder, so that the key, irrespective of which web face is right and which left, can be inserted into the keyway. These camming shoulders are advantageously so made on a duplicating milling machine that the shoulders, as shown in FIG. 7, are composed of straight sections. When the key is inserted into the keyway 3, the tumblers 5, 6, and 7, are moved from their locking positions, illustrated in FIGS. 2 and 5, into their unlocking position, illustrated in FIGS. 1 and 6, in which the tumblers do not project beyond the surface of the plug.

The tumblers of each set can be so constructed, for example, that the tumbler 7 is positively operated only by the key web 13, the tumbler 6 by the camming shoulder 15, and the tumbler 5 by the camming shoulder 14. To this end, the disc tumbler 7 embodies a rectangular opening 16 having a height somewhat greater than the height X of the key web 13 and a width somewhat greater than the total width Y of the key. The openings 17 and 18 of the disc tumblers 6 and 5 comprise lateral recesses 17a and 18a, which are engaged by the camming shoulders 14 and 15.

As the key 8 is pushed into the keyway 3, the web 13 pushes the tumblers 7 to their unlocking position while it moves the tumblers 5 and 6 to intermediate positions. These latter tumblers are moved to their final, unlocking position by the shoulders l4 and 15.

A very great number of key changes is possible by changing the shape of the camming shoulders on the key and by using the same shoulder shape, but shifting the shoulders up and down and lengthwise of the key web.

Since the key web moves at least some of the tumblers to an intermediate position, or presets them, as the key is inserted, it is possible to have these tumblers project relatively far out of the plug, thereby increasing the security afforded by the look.

In accordance with the invention, the number of tumblers comprising a set in a slot 4 can be greater than three.

Although the preferred embodiment of the invention has been described, the scope of, and the breadth of protection afforded to, the invention are limited solely by the appended claims.

I claim:

1. A locking device comprising a lock and key, said lock comprising a housing, a cylindrical plug rotatably supported in said housing, said plug having a longitudinal channel adapted for receiving said key, a plurality of tumblers slidably supported in said plug transversely of said channel, and means for biasing said tumblers outwardly of said plug, said housing having a recess adapted for receiving said tumblers biased outwardly of said plug to prevent said plug from rotating, each of said tumblers having an opening adapted for receiving said key, said key including first means for passing through each said opening in each of said tumblers as said key is inserted in said plug, said first means of said key being engageable with a first of said tumblers in opposition of said biasing means to partially withdraw said first tumbler from said recess in said housing to a first position of partial withdrawal, said first means of said key being engageable with a second of said tumblers adjacent said first tumbler in opposition of said biasing means to fully withdraw said second tumbler from said recess in said housing while maintaining said first tumbler in said first position of partial withdrawal and said key further including second means for engaging said first tumbler partially withdrawn from said recess in said housing to fully withdraw said first tumble from said recess in said housing, whereby said plug is free to rotate in said housing.

2. A locking device as claimed in 1 wherein said first and second means of said key include camming projections, at least one of said tumblers including a camming recess adapted for cooperatively receiving said camming projections to slidably respond relative thereto.

3. A locking device as claimed in claim 2 wherein said camming recess includes a pair of opposed shoulders engageable by one of said camming projections, one of said shoulders being adapted for compelling the withdrawal of the respective tumbler from said recess in said housing as said key'is inserted into said plug, the other of said shoulders being adapted for compelling the return of the respective tumbler into said recess in said housing as said key iswithdrawn from said plug.

43. A locking device as claimed in claim 1 wherein said housing is provided with a further recess opposing the first-named recess, at least two of said tumblers being slidable in opposite directions relative to one another each into a respective recess in said housing.

5. A locking device as claimed in (including three said tumblers, two of said tumblers being slidable to one of said recesses, the other tumbler being slidable to the other recess.

6. A locking device as claimed in claim 5 wherein said resilient means includes a first spring interposed between two of said tumblers for urging each in opposite directions, to respective recesses, and a second spring interposed between said housing and the remaining tumblers for urging same toward one of said recesses.

7. A locking device as claimed in claim 6 including at least two adjacent groups of said three tumblers, each group including two outermost tumblers and a middle tumbler interposed between said outermost tumblers, said first spring being interposed between one outermost tumbler of one group and the other outermost member of the adjacent group, said second spring being interposed between said housing and said middle tumbler. 

1. A locking device comprising a lock and key, said lock comprising a housing, a cylindrical plug rotatably supported in said housing, said plug having a longitudinal channel adapted for receiving said key, a plurality of tumblers slidably supported in said plug transversely of said channel, and means for biasing said tumblers outwardly of said plug, said housing having a recess adapted for receiving said tumblers biased outwardly of said plug to prevent said plug from rotating, each of said tumblers having an opening adapted for receiving said key, said key including first means for passing through each said opening in each of said tumblers as said key is inserted in said plug, said first means of said key being engageable with a first of said tumblers in opposition of said biasing means to partially withdraw said first tumbler from said recess in said housing to a first position of partial withdrawal, said first means of said key being engageable with a second of said tumblers adjacent said first tumbler in opposition of said biasing means to fully withdraw said second tumbler from said recess in said housing while maintaining said first tumbler in said first position of partial withdrawal and said key further including second means for engaging said first tumbler partially withdrawn from said recess in said housing to fully withdraw said first tumble from said recess in said housing, whereby said plug is free to rotate in said housing.
 2. A locking device as claimed in 1 wherein said first and second means of said key include camming projections, at least one of said tumblers including a camming recess adapted for cooperatively receiving said camming projections to slidably respond relative thereto.
 3. A locking device as claimed in claim 2 wherein said camming recess includes a pair of opposed shoulders engageable by one of said camming projections, one of said shoulders being adapted for compelling the withdrawal of the respective tumbler from said recess in said housing as said key is inserted into said plug, the other of said shoulders being adapted for compelling the return of the respective tumbler into said recess in said housing as said key is withdrawn from said plug.
 4. A locking device as claimed in claim 1 wherein said housing is provided with a further recess opposing the first-named recess, at least two of said tumblers being slidable in opposite directions relative to one another each into a respective recess in said housing.
 5. A locking device as claimed in 4 including three said tumblers, two of said tumblers being slidable to one of said recesses, the other tumbler being slidable to the other recess.
 6. A locking device as claimed in claim 5 wherein said resilient means includes a first spring interposed between two of said tumblers for urging each in opposite directions, to respective recesses, and a second spring interposed between said housing and the remaining tumblers for urging same toward one of said recesses.
 7. A locking device as claimed in claim 6 including at least two adjacent groups of said three tumblers, each group including two outermost tumblers and a middle tumbler interposed between said outermost tumblers, said first spring being interposed between one outermost tumbler of one group and the other outermost member of the adjacent group, said second spring being interposed between said housing and said middle tumbler. 